What Are Parking Mandates?

Parking mandates, also known as parking minimums, are zoning regulations that require developers to build a minimum number of parking spaces with new housing and commercial developments. These mandates typically specify a certain number of parking spaces per unit of housing, square footage of retail space, or other metrics depending on the development type.

Why Parking Mandates Are Costly:

  • Increased Housing Costs: Each parking space can cost $30,000-$75,000 to build, significantly raising the cost of housing development and ultimately housing prices.
  • Reduced Housing Supply: Land used for parking cannot be used for additional housing units, limiting the overall housing supply.
  • Environmental Impact: Excessive parking encourages car dependency, increasing traffic congestion and carbon emissions.
  • Inefficient Land Use: Parking lots create “dead spaces” in urban areas that could otherwise be used for housing, businesses, or public spaces.
  • Economic Burden: Many parking spaces sit empty much of the time, representing wasted resources and opportunity costs.

Why Parking Mandates Should Be Repealed:

  • Market-Based Solutions: Developers can better determine the appropriate amount of parking based on actual demand rather than arbitrary requirements.
  • Transit-Oriented Development: Eliminating parking mandates near transit encourages development that leverages existing public transportation infrastructure.
  • Affordability: Reducing or eliminating parking requirements can make housing more affordable and accessible.
  • Sustainability: Less parking promotes walking, cycling, and public transit use, reducing carbon emissions.
  • Vibrant Communities: Space previously dedicated to parking can be repurposed for housing, businesses, and community amenities.

Enter: The People Over Parking Act

Interactive Map: Areas Affected by the Updated People Over Parking Act

## 
## === Creating Interactive Map ===
## 
## Adding agency hub buffer layers...
## Interactive map created successfully

This analysis examines the potential impact of new legislation passed in Illinois (SB2111) on Chicagoland.

According to the updated bill 10400SB2111ham003, minimum parking requirements are prohibited for development projects located within:

Analysis Methodology

This analysis implements the following methodology to identify qualifying transit hubs and corridors:

Peak Period Definition:

  • Morning peak: 7:00 AM - 9:00 AM (120 minutes)
  • Afternoon peak: 4:00 PM - 6:00 PM (120 minutes)
  • Service is analyzed separately for each period; locations qualify if they meet frequency thresholds in either AM or PM

Stop Clustering (Bus Hubs Only):

  • Bus stops within 150 feet of each other are spatially clustered to represent physical intersections
  • This prevents overcounting stops at the same street corner and aligns with the statutory concept of “an intersection of 2 or more bus routes”
  • Clustering uses Illinois State Plane East projection (EPSG:3435) for accurate distance measurement

Route Overlap Verification (Bus Hubs Only):

  • After clustering, we verify that routes actually overlap at the same physical intersection or street
  • Stop names (e.g., “Jackson & Lotus”, “Oak Ave & Davis St”) are parsed to extract street names
  • A cluster qualifies only if 2 or more routes share at least one common street name
  • This ensures routes truly intersect at the location, not just have nearby stops within 150 feet
  • Example: Route A stops at “State & Madison”, Route B stops at “State & Monroe” (both within 150ft) → they share “State” street → overlap verified

Combined Frequency Calculation:

  • For each stop cluster (hubs) or individual stop (corridors), we count total trips across all routes during each peak period
  • Combined service interval = peak period duration (120 min) ÷ total trips
  • Example: 8 trips in 2 hours = 120 ÷ 8 = 15 minute average interval

Qualification Criteria:

  • Bus Hubs: Must have 2 or more routes AND combined frequency ≤ 15 minutes in at least one peak period AND routes must overlap on same street/intersection
  • Bus Corridors: Must have 1 or more routes AND combined frequency ≤ 15 minutes in at least one peak period
  • Rail Hubs: All rail stations within Illinois automatically qualify (CTA rail, Metra, and Metro St. Louis MetroLink)

Direction Handling:

  • If GTFS direction_id data is available, routes are analyzed by direction (northbound/southbound, eastbound/westbound)
  • This provides more accurate service frequency calculations at directional stops

Geographic Boundaries and Clipping:

  • All transit hub and corridor buffers are clipped to Illinois state boundaries
  • This ensures parking mandate relief applies only to areas within Illinois jurisdiction
  • Metro St. Louis transit system operates across the Illinois-Missouri border; only Illinois portions of hub/corridor buffers are included in the analysis
  • Metra serves some stations in Wisconsin (Kenosha County); these are excluded from the analysis (latitude filter at 42.5°)
  • Clipping is performed after buffer creation using the U.S. Census TIGER/Line state boundary for Illinois

Data Sources:

  • Chicago area: CTA, Pace, and Metra GTFS (General Transit Feed Specification) data
  • St. Louis area: Metro St. Louis GTFS data (includes MetroLink light rail and MetroBus)
    • Note: Metro St. Louis operates in both Missouri and Illinois; only Illinois portions are included after geographic clipping
  • Champaign-Urbana: CUMTD (Champaign-Urbana Mass Transit District) GTFS data
  • Rockford: RMTD (Rockford Mass Transit District) GTFS data
  • TIGER/Line street network data from U.S. Census Bureau via tigris package
  • Analysis covers 11 Illinois counties:
    • Chicago metro: Cook, DuPage, Kane, Lake, McHenry, and Will
    • St. Louis metro: St. Clair, Madison, and Monroe
    • Champaign-Urbana: Champaign
    • Rockford: Winnebago

Summary Statistics

Bus Transit Hubs

Methodology: Stops clustered at 150 ft radius; qualifies if 2+ routes AND combined frequency ≤15 min in EITHER AM (7-9am) or PM (4-6pm) peak period.

CTA:

  • Bus hub stops: 4717 (in 1369 clusters)
  • Average routes per cluster: 2.8 (AM) / 2.8 (PM)
  • Average service interval: 4.7 min (AM) / 4.9 min (PM)

Pace:

  • Bus hub stops: 2799 (in 715 clusters)
  • Average routes per cluster: 2.5 (AM) / 2.5 (PM)
  • Average service interval: 9.9 min (AM) / 9.7 min (PM)

Metro St. Louis:

  • Bus hub stops: 155 (in 43 clusters)
  • Average routes per cluster: 2.2 (AM) / 2.2 (PM)
  • Average service interval: 10.6 min (AM) / 11.1 min (PM)

Champaign-Urbana MTD:

  • Bus hub stops: 1235 (in 367 clusters)
  • Average routes per cluster: 3.3 (AM) / 2.8 (PM)
  • Average service interval: 10.1 min (AM) / 9.4 min (PM)

Rockford MTD:

  • Bus hub stops: 73 (in 20 clusters)
  • Average routes per cluster: 7.4 (AM) / 7.4 (PM)
  • Average service interval: 8.9 min (AM) / 9.0 min (PM)

Rail Stations: 715 - CTA: 464 - Metra: 240 - Metro STL: 11

Total Transit Hubs: 11,240

Bus Corridors

Methodology: Individual stops (no clustering); qualifies if combined frequency ≤15 min in EITHER AM (7-9am) or PM (4-6pm) peak period.

CTA:

  • Corridor stops: 9,342
  • Average routes per stop: 1.3 (AM) / 1.3 (PM)
  • Average service interval: 9.7 min (AM) / 9.9 min (PM)

Pace:

  • Corridor stops: 1,863
  • Average routes per stop: 1.6 (AM) / 1.6 (PM)
  • Average service interval: 14.3 min (AM) / 13.7 min (PM)

Metro St. Louis:

  • Corridor stops: 382
  • Average routes per stop: 2.2 (AM) / 2.2 (PM)
  • Average service interval: 11.6 min (AM) / 11.7 min (PM)

Champaign-Urbana MTD:

  • Corridor stops: 763
  • Average routes per stop: 2.3 (AM) / 2.1 (PM)
  • Average service interval: 14.2 min (AM) / 10.1 min (PM)

Rockford MTD:

  • Corridor stops: 38
  • Average routes per stop: 2.8 (AM) / 2.8 (PM)
  • Average service interval: 13.1 min (AM) / 13.4 min (PM)

Geographic Coverage

  • Hub buffer area (1/2 mile): 653.2 sq mi (9.22% of total area)
  • Corridor buffer area (1/8 mile): 481.2 sq mi (6.79% of total area)
  • Combined affected area: 821.4 sq mi (11.59% of total area)
  • Total Illinois area analyzed:
    • Chicago MSA (6 counties): 3744.5 sq mi
    • St. Louis MSA (3 IL counties): 1814.3 sq mi
    • Champaign-Urbana (1 county): 1008.0 sq mi
    • Rockford (1 county): 519.0 sq mi
    • Total: 7085.8 sq mi

Note: Area calculations reflect only portions within Illinois state boundaries. Cross-border transit services (Metro St. Louis in Missouri, Metra in Wisconsin) are excluded through geographic clipping.

Notes on Updated Methodology

This analysis implements the following improvements to align with SB 2111’s statutory language:

  1. Split AM/PM Peak Periods: Service is analyzed separately for morning (7-9am) and afternoon (4-6pm) peak periods, then combined using “either” logic—a location qualifies if it meets the frequency threshold in either AM or PM.

  2. Stop Clustering (Hubs Only): Bus stops within 150 feet are clustered together to represent physical intersections. This prevents overcounting stops at the same intersection and better reflects the statutory concept of “an intersection of 2 or more bus routes.”

  3. Direction-Aware (if available): If direction_id is present in GTFS data, the analysis accounts for directionality (northbound vs southbound) when calculating service frequency.

  4. Qualification Criteria:

    • Bus Hubs: Must have 2+ routes AND combined frequency ≤15 minutes in at least one peak period
    • Bus Corridors: Must have 1+ routes AND combined frequency ≤15 minutes in at least one peak period
  5. Transparent Metrics: Each hub and corridor stop now includes diagnostic information showing AM/PM service levels, making it easy to verify which locations qualify and why.

  6. Illinois Boundary Clipping: All hub and corridor buffer areas are clipped to Illinois state boundaries after calculation. This is critical for cross-border transit agencies (Metro St. Louis, Metra) to ensure parking mandate relief applies only within Illinois jurisdiction. Area calculations reflect only the Illinois portions of buffer zones.